Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
  • C03B37/01—Manufacture of glass fibres or filaments
  • C03B37/04—Manufacture of glass fibres or filaments by using centrifugal force, e.g. spinning through radial orifices; Construction of the spinner cups therefor
  • C03B37/05—Manufacture of glass fibres or filaments by using centrifugal force, e.g. spinning through radial orifices; Construction of the spinner cups therefor by projecting molten glass on a rotating body having no radial orifices
  • C03B37/055—Manufacture of glass fibres or filaments by using centrifugal force, e.g. spinning through radial orifices; Construction of the spinner cups therefor by projecting molten glass on a rotating body having no radial orifices by projecting onto and spinning off the outer surface of the rotating body

Definitions

• the invention relates to a device for manufacturing mineral fibers from a stretchable material, by centrifugation.
• free centrifugation in which the material to be fiberized is led in the molten state from the outside, to the periphery of the fiber-drawing rotor and is driven by these rotors to detach from it in the form of fibers. under the effect of centrifugal force.
• EP-B2-0 059 152 EP-B2-0 059 152.
• Centrifuge rotors are subjected to high temperatures due to contact with the molten material. These high temperatures must not however be such as to cause deformation and / or wear detrimental to the positioning of these rotors. This is why traditional devices described in the aforementioned application comprise cooling means, constituted in particular by the arrangement of a circulation of water by the shaft of the rotor and up to the internal face of the peripheral part of the rotor.
• European patent EP-B-0 195 725 presents in detail the system for supplying cooling water to a centrifuge rotor which also has a binder supply inside the rotor intended to ensure the cohesion of the fibers between them. inside the mattress they constitute.
• the pipe concentric with the axis of the rotor which brings the water ends in the plane of symmetry of the rotor by an enlarged cavity from which the water escapes by a hole to gain the interior space of the rotor and to be directed by centrifugal force towards orifices which open, on either side, on the lateral faces.
• the cooling system common to the two previous documents fulfills its role perfectly and makes it possible to significantly extend the life of the centrifuge rotors. But if the cooling is generally effective, the temperature gradients are large on the rim where the liquid vitrifiable material is deposited. Indeed, the material is deposited and stays on a strip of a certain width before being expelled, either in the form of fibers, or in the form of drops projected towards the following rotor.
• Patent application WO 95/07243 proposes a centrifugation rotor intended to produce mineral fibers which is itself of a design very different from the previous ones. It has more the shape of a drum than that of a wheel, its thickness along the axis being substantially greater than its largest diameter.
• the diameter of the area which is covered by the material to be fiberized is variable.
• the molten material is deposited at one end of the drum, where the diameter is small and progresses along the axis to the area of fiber formation, at the other end, where the diameter is greater.
• orifices located at the periphery of the drum, allow water in the form of vapor to exit.
• the purpose of the entire device is to obtain fibers whose diameter varies little from one fiber to another.
• the orifices which allow steam to escape facilitate the cooling of the fiber material which covers them as well as of the sleeve itself in this area.
• the effect of the vapor outlet through the orifices is to increase the thermal gradient on the sleeve.
• the object which the invention sets itself the task of achieving is to reduce the thermal gradients in the axial direction of the rim of the centrifuge rotors.
• the invention provides a fiberizing rotor fitted to a machine for the manufacture of mineral fibers by external centrifugation, the rotor comprising a rim outside which the material to be fiberized in the molten state is brought from either distribution rotor, or another fiberizing rotor, the rotor comprising an internal liquid circuit with orifices for the evacuation of the liquid located on the rim, in which the orifices are located in the part of the rim to which is brought the material to be fiberized.
• the orifices are arranged on the rim at least in two rows located in parallel planes and, advantageously, the rotor has two rows located symmetrically with respect to the plane of symmetry of the rim.
• the invention also provides means for dispensing liquid, making it possible to supply each of the rows of orifices and advantageously, the dispensing means supplying a row of orifices being a row of dispensing holes situated in a plane parallel to that of the row of holes.
• the preferred embodiment of the rotor of the invention provides that it comprises a liquid supply chamber in two parts, a supply compartment and a distribution compartment, they are then connected by the holes of distribution.
• the distribution holes have a total cross section smaller than the total cross section of the rim orifices.
• the distribution holes are distributed in two rows situated in planes which are on either side of the planes of the rows of holes in the rim, also at number two.
• the rotor laterally has holes for direct exit, distributed in a circle centered on the axis of the rotor, located on the side of the rotor where the fibers are ejected and that, preferably, the direct exit holes feed a circular groove of greater radius.
• the total section of the direct outlet holes and that of the distribution holes are of the same order, the second being preferably greater.
• These direct lateral outlet holes are generally located on the flange which constitutes the lateral wall of the rotor.
• Figure 1 shows a view of a fiberizing machine with two fiber rotors
• Figure 2 a section of a centrifuge rotor according to the invention
• FIG. 3 an estimated distribution curve of the temperatures at the surface of the rim of the same rotor.
• FIG. 1 shows a fiberizing device of the type used according to the invention and which comprises three centrifuge rotors 1, 2, 3, two successive rotors rotating in opposite directions to one another. Devices of the same type with four centrifuge rotors are also commonly used.
• the material to be fiberized 4 in the molten state is poured either through a chute 5 or from the orifice of a stabilizing tank on the first centrifuge rotor 1 which is also called distribution rotor because it does not produce practically no fibers and essentially has the role of accelerating and distributing the material to be fiberized 4 on the following rotor 2 to which it is sent and where it partially adheres.
• the adherent molten material detaches from the rotor 2 under the effect of centrifugal force and then forms filaments which are entrained by the gas current generated by the orifices of the blowing crown 6 and / or by a drawing lip, then that the non-adherent material is returned to the following centrifugation rotor 3 for the production, in the same way, of additional fibers.
• the gas stream carrying the fibers is directed transversely to the direction of projection of the fibers out of the rotor. Thanks to the projection member 7, the binder composition is projected by centrifugation in the form of droplets into the gas stream which finely divides it so that the fibers formed are uniformly coated.
• centrifuge rotors are water cooled, preferably with cooling water flow rates adjusted for each rotor as a function of the equilibrium temperature to be reached. Normally, the temperature of the rotors in contact with the molten material decreases from the first 1 to the last 3.
• the invention relates to centrifuge rotors and their liquid circulation cooling system.
• Traditional centrifuge rotors such as those described in patent EP-B-0 195 725, usually consist of a hub through which the fluids - cooling water and binder - are brought, a rim at the periphery of which the material to be fiberized, in the molten state, is distributed and from two flanges, on both sides of the rotor which are associated, on the one hand with the hub and on the other hand with the rim, to constitute a kind of internal chamber (the rotor is hollow), at the interior of which the coolant circulates before being ejected through orifices generally located in the flanges.
• the fiber-drawing rotors generally also include, in addition, in the central part of the rotor on the discharge side of the fibers, a member 7 for projecting the liquid binder (see patent EP-B-0 059 152) which will not be discussed. here.
• the centrifuge rotor of the invention is fitted with outlets for the coolant - water in most cases - on the periphery of the rim itself.
• outlets for the coolant - water in most cases - on the periphery of the rim itself.
• FIG. 2 we see such orifices at 8, 9, they are drilled through the rim in zones 10, 11 which have been specially thinned.
• This configuration allows very effective cooling of the central part of the rim, where the contribution of calories by the material to be fiber-molten is the most important.
• These holes open into the rim surface with its usual structure.
• the rim is shown with circular ridges 12 located in planes perpendicular to the axis of the rotor, but any other structure favorable to good fiber drawing is compatible with the invention.
• FIG. 2 represents the preferred embodiment of the invention, that is to say that, on the one hand, the rows of orifices are separated by a sort of partition 30 which makes it possible to supply each row separately and that, on the other hand, the hollow part inside the rotor is separated into two compartments, a supply compartment 13 and a distribution compartment 14.
• the two compartments 13, 14, communicate by connecting holes 15, 16.
• the supply compartment 13 receives the coolant in a conventional manner through the hub of the rotor, not shown. By the effect of centrifugal force, the liquid is sprayed on the periphery of the compartment 13, where the holes 15, 16 are located.
• the flow of supply of the coolant is preferably such that it allows the creation of a reserve of liquid in compartment 13, which guarantees that the flow rate of holes 15, 16 and 19 is permanent and that it is the same over the entire periphery of compartment 13.
• the liquid, leaving holes 15 , 16, is projected by centrifugal force into the axis of these holes and preferably arrives on the walls of the distribution compartment respectively 17, 18, which constrict towards the periphery of the rotor and thus allow the coolant to progress - still thanks to centrifugal force - towards the orifices 8, 9, by "licking" the walls 17, 18, which it cools before leaving the inside of the rotor on the rim.
• the “partition” 30, between the two rows of orifices, makes it possible to guarantee that each of the rows is supplied.
• the two compartments are shown in the figure as if they were watertight boxes. This is not a necessity, the centrifugal force indeed drives the water systematically in a radial direction parallel to the plane of symmetry of the rotor.
• the orifices 8, 9, formed two circular rows of 120 holes each with a diameter of 1.2 mm.
• a first row 8 was located on one side of the plane of symmetry of the rotor, the other 9, symmetrically, on the discharge side of the fibers.
• the partition wall of the two compartments 13, 14 was itself pierced with two circular rows of 10 holes each with a diameter of 0.9 mm. It can thus be seen that all of the orifices on the rim have a total section of 271 mm 2 while their supply, thanks to the connection holes 15, 16, takes place with a much smaller overall section, of 12.7 mm 2 .
• This choice of the respective sections makes it possible to prevent the coolant from stagnating in the distribution chamber where it would risk to heat and possibly to vaporize with the disturbances which could result therefrom.
• the constitution of a liquid reserve in the supply compartment thanks to the adjustment of the liquid flow rate, ensures the permanence of the supply.
• the two supply 13 and distribution 14 compartments constitute an embodiment of the invention. It is also possible to directly supply the rows of orifices 8, 9, from the zones 10, 11, separated by the partition 30, by installing supply holes which play the same role as the holes 15, 16, but which are located on the pipe concentric with the axis of the rotor (cf. document EP-B-0 195 725). Other tests have been carried out with rows of orifices on the rim arranged asymmetrically with respect to the plane of symmetry of the rotor. The results were also satisfactory.
• a hole that is part of a circular row of direct outlet holes it provides additional cooling from the outside of the side of the fiber-drawing rotor, on the side of the fiber discharge.
• the holes 19 have, on the prototype, a diameter of 0.9 mm and they are 10 in number. Their overall section is thus 6.4 mm 2 which is less than the overall section of the connecting holes 15, 16 (12.7 mm 2 ) but not very far from this section.
• a circular gutter 32 has been arranged above the holes 19 which collects the liquid from the hole 19 and distributes it over a wider sector.
• the hole 19 opens back with respect to the gutter 32 and above all, with respect to the edge of the rim, which allows the liquid to extract calories on a large surface of the lateral face of the rotor before leaving it. .
• the system of the invention is much more efficient and allows to use only 250 liters of water per hour instead of the usual 350 - 400 liters.
• FIG. 3 shows the likely profile of the temperatures at the surface of the rim. Measuring the actual temperature profile of the metal on the rim surface under the molten material is very delicate. This is an estimate, the most likely one, which is entirely compatible with the results of the experimentation of the centrifuge rotors according to the invention in production, results which will be discussed below. Two curves are shown:
• the cooling is less effective at the center of the rim, between the limits 20, 21, between which the molten material is deposited.
• This second temperature is here 1230 ° C., that is to say that the working stage is 260 ° C.
• Such a composition fiberized on centrifuge rotors according to the invention makes it possible to obtain fibers which are substantially longer than with traditional rotors.
• the fasonaire is a size used by all rock wool producers, which makes it possible to assess the overall fineness and length of the fibers. It is measured using a so-called "fascial" device, for example, that of the company AVIATEST NIEBERDING in Germany.
• the test piece is a tuft of mineral wool free from binder or oil, of given mass, which may include non-fibrous components (slugs, sand, etc.) imposed by certain fiberizing processes. It is compressed in a cylindrical chamber of volume 11 predetermined. A gas stream is passed through the specimen - dry air or nitrogen. The gas flow rate being kept constant, the pressure drop across the test piece is measured using a water column graduated in conventional units.
• the primary mattress is a manufacturing stage when the mattresses are produced in two stages, constitution of a first primary layer of fibers and liquid binder (it is as thin as possible) then deposition of several thicknesses of the primary zigzag , perpendicular to the axis of the final mattress.
• the performance of the finished mattress is all the better the greater the number of primary plies, that is to say all other things being equal, the lower the unit surface mass. With usual production, we are limited downwards for the surface mass of the primary water table
• the invention allows it to easily descend under the same production conditions to lower values, which significantly improves the quality of the mattress finished.
• a typical weight composition is, for example:
• rock wool compositions are particularly difficult to fiberize. This is particularly the case for those that dissolve faster in body fluids.
• the rotors of the invention made it possible to stabilize the installation and to fiber for hours on end without interruption. They thus provide a solution to an important problem of health and the environment.
• the device of the invention by virtue of the reduction in temperature gradients on the rim of the centrifuge rotors, under the meltable fiber material, makes it possible to significantly improve the manufacturing conditions, both for the quality produced ( length of the fibers and delay in the decline in quality due to wear of the rotor) only for the stability of the conditions (compositions with a narrow working bearing in particular) or for the wear of the material.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Spinning Or Twisting Of Yarns (AREA)
• Manufacture, Treatment Of Glass Fibers (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9485860

Family Applications (1)

Country Status (9)

Family Cites Families (3)

• 1995
  • 1995-12-22 FR FR9515365A patent/FR2742744A1/fr active Pending
• 1996
  • 1996-12-12 CN CN96192070A patent/CN1175934A/zh active Pending
  • 1996-12-12 CZ CZ972515A patent/CZ251597A3/cs unknown
  • 1996-12-12 EP EP96942393A patent/EP0810979A1/fr not_active Withdrawn
  • 1996-12-12 PL PL96321844A patent/PL321844A1/xx unknown
  • 1996-12-12 SK SK1136-97A patent/SK113697A3/sk unknown
  • 1996-12-12 AU AU11789/97A patent/AU718773B2/en not_active Ceased
  • 1996-12-12 WO PCT/FR1996/001989 patent/WO1997023421A1/fr not_active Application Discontinuation
• 1997
  • 1997-08-21 NO NO973855A patent/NO973855L/no unknown

Non-Patent Citations (1)

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